The present invention relates to a method for control of support gaps for a magnetic levitation vehicle, and also to a magnetic levitation vehicle with a control circuit operating with said method.
The invention relates to a method pursuant to the preamble of claim 1 and to a magnetic levitation vehicle pursuant to the preamble of claim 4.
Magnetic levitation vehicles, particularly those equipped with long stator linear motors, have a number of carrying (supporting) magnets mounted in the direction of travel and facing a guideway for the magnetic levitation vehicle, particularly a long stator mounted to it. For operation of the magnetic levitation vehicle, the carrying magnets are activated at first in order to form support gaps of a given height between the guideway and the magnetic levitation vehicle (e.g. 10 mm). Next the magnetic levitation vehicle is set in motion, for which purpose the carrying magnets in case of long stator linear motors simultaneously supply the excitation field for the linear motor (e.g. DE 39 17 058 C1). Compliance with the nominal values defined for the support gaps is assured by gap sensors (e.g. DE 35 16 036 C2) and control circuits connected to them which control the electrical currents in the windings of the carrying magnets in such a manner that the support gaps during operation substantially retain the same size (e.g. “Magnetschnellbahn Transrapid-Technik und System”, Thyssen Transrapid GmbH, MSB Tr10/96).
The carrying magnets of such magnetic levitation vehicles are generally mounted to support brackets which in turn are fastened to suspension frames or the like for a car body. The mechanical setup is preferably so chosen that two support brackets each are provided at the longitudinal ends of the suspension frames and fastened to different carrying magnets in a way that at least two neighbouring carrying magnets act there upon the suspension frame.
On account of unavoidable tolerances, e.g. in the sensor signals indicating the actual values of the support gaps, in the control circuits connected with the sensors as well as in the mechanical structure, it may happen that the windings of neighbouring carrying magnets are flown through by differently high electrical currents, although they establish the same support gap. This is undesirable, because different electrical currents lead to different loads of the windings, e.g. due to heat development.